1. Field of the Invention
This invention relates to air conditioning and/or heating and more particularly to a control circuit for controlling an air conditioning or heating system.
2. Description of the Prior Art
Various types of apparati have been devised in the prior art in an attempt to deactivate a thermostat of an air conditioning or heating system for a period of time in order to reduce operational cost. Various types of mechanical timers have been incorporated to enable the thermostat to operate for a first period of time and to deactivate the thermostat for a second period of time. Electronic circuits have also been devised to accomplish the same or similar tasks. Unfortunately, these devices were not synchronized with the operation or status of the thermostat and accordingly the compressor could be subjected to rapid starting and stopping creating excessive pressures within the compressor. Many air conditioning experts hesitate to recommend mechanical cyclers due to the possibilities of the excessive pressures created within the compressor due to the rapid starting and stopping of the compressor.
In an attempt to overcome this hazard, others in the prior art have developed circuits which prohibit operation of the compressor for a given period of time after the compressor has terminated operation.
Others in the prior art have developed line voltage sensors for terminating operation of the compression upon a reduction of line voltage. Unfortunately, the aforementioned contributions of the prior art have never been consolidated into a single and inexpensive unit. Most of the prior art units were overly complex and unreliable and accordingly, did not find widespread use in the industry. Examples of prior art patents relating to the present invention include U.S. Pat. Nos. 3,625,020; 3,628,346; 3,636,369; 3,640,085; 3,673,811; 3,707,611; 3,721,866; 3,721,880; 3,777,240; 3,817,052; 3,864,611; 3,946,574; 4,028,593; 4,034,570; 4,045,973; 4,094,166; 4,102,389 and 4,128,854.
In my prior U.S. Pat. No. 4,288,990 issued Sept. 15, 1981, I disclosed a novel control unit incorporating a time cycler with interrelated safety features to protect the compressor from damage. In addition, my prior invention utilized a presence sensor for altering the time cycle in accordance with the occupancy of the air conditioned or heated region.
It is an object of the present invention to provide an improvement to my prior invention which results in a superior control circuit for many installations and is a further advancement to the air conditioning and heating art.
Another object of this invention is to provide an apparatus for controlling an air conditioning and/or heating system in accordance with time, activity and temperature.
Another object of this invention is to provide an apparatus for controlling an air conditioning and/or heating system for deactivating the compressor or heater when the source voltage is reduced below a preselected minimum power level.
Another object of this invention is to provide an apparatus for controlling an air conditioning and/or heating system for terminating operation of the compressor in the event of loss of one phase of a plural phase power source.
Another object of this invention is to provide an apparatus for controlling an air conditioning and/or heating system in accordance with the activity within the area being air conditioned or heated.
Another object of this invention is to provide an apparatus for controlling an air conditioning and/or heating system which is more sensitive and a more simplified circuit than my prior invention.
Another object of this invention is to provide an apparatus for controlling an air conditioning and/or heating system which establishes a first and a second preferred temperature range whereby the air conditioning and/or heating system is controlled within the first preferred temperatures range during occupancy of the air conditioned or heated region and is controlled within the second preferred temperature range during non-occupancy of the air conditioned or heated region.
The foregoing has outlined some of the more pertinent objects of the invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly other objects and a fuller understanding of the invention may be had by referring to the summary of the invention and the detailed description describing the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.